Re: [PATCH] scsi-disk: define props in scsi_block_disk to avoid memleaks

[Pan Nengyuan]

On 1/14/2020 6:56 AM, John Snow wrote:
> CC qemu-block
> 
> On 1/13/20 1:20 AM, address@hidden wrote:
>> From: Pan Nengyuan <address@hidden>
>>
>> scsi_block_realize() use scsi_realize() to init some props, but
>> these props is not defined in scsi_block_disk_properties, so they will
>> not be freed.
>>
>> This patch defines these prop in scsi_block_disk_properties and aslo
>> calls scsi_unrealize to avoid memleaks, the leak stack as
>> follow(it's easy to reproduce by attaching/detaching scsi-block-disks):
>>
>> =================================================================
>> ==qemu-system-x86_64==32195==ERROR: LeakSanitizer: detected memory leaks
>>
>> Direct leak of 57 byte(s) in 3 object(s) allocated from:
>>   #0 0x7f19f8bed768 (/lib64/libasan.so.5+0xef768)  ??:?
>>   #1 0x7f19f64d9445 (/lib64/libglib-2.0.so.0+0x52445)  ??:?
>>   #2 0x7f19f64f2d92 (/lib64/libglib-2.0.so.0+0x6bd92)  ??:?
>>   #3 0x55975366e596 (qemu-system-x86_64+0x35c0596)  
>> /mnt/sdb/qemu/hw/scsi/scsi-disk.c:2399
>>   #4 0x559753671201 (emu-system-x86_64+0x35c3201)  
>> /mnt/sdb/qemu/hw/scsi/scsi-disk.c:2681
>>   #5 0x559753687e3e (qemu-system-x86_64+0x35d9e3e)  
>> /mnt/sdb/qemu/hw/scsi/scsi-bus.c:58
>>   #6 0x55975368ac44 (qemu-system-x86_64+0x35dcc44)  
>> /mnt/sdb/qemu/hw/scsi/scsi-bus.c:216
>>   #7 0x5597532a7840 (qemu-system-x86_64+0x31f9840)  
>> /mnt/sdb/qemu/hw/core/qdev.c:876
>>
>> Direct leak of 15 byte(s) in 3 object(s) allocated from:
>>   #0 0x7f19f8bed768 (/lib64/libasan.so.5+0xef768)  ??:?
>>   #1 0x7f19f64d9445 (/lib64/libglib-2.0.so.0+0x52445)  ??:?
>>   #2 0x7f19f64f2d92 (/lib64/libglib-2.0.so.0+0x6bd92)  ??:?
>>   #3 0x55975366e06f (qemu-system-x86_64+0x35c006f)  
>> /mnt/sdb/qemu/hw/scsi/scsi-disk.c:2388
>>   #4 0x559753671201 (qemu-system-x86_64+0x35c3201)  
>> /mnt/sdb/qemu/hw/scsi/scsi-disk.c:2681
>>   #5 0x559753687e3e (qemu-system-x86_64+0x35d9e3e)  
>> /mnt/sdb/qemu/hw/scsi/scsi-bus.c:58
>>   #6 0x55975368ac44 (qemu-system-x86_64+0x35dcc44)  
>> /mnt/sdb/qemu/hw/scsi/scsi-bus.c:216
>>
>> Reported-by: Euler Robot <address@hidden>
>> Signed-off-by: Pan Nengyuan <address@hidden>
>> ---
>>  hw/scsi/scsi-disk.c | 8 +++++---
>>  1 file changed, 5 insertions(+), 3 deletions(-)
>>
>> diff --git a/hw/scsi/scsi-disk.c b/hw/scsi/scsi-disk.c
>> index e44c61eeb4..caec99ae20 100644
>> --- a/hw/scsi/scsi-disk.c
>> +++ b/hw/scsi/scsi-disk.c
>> @@ -2981,7 +2981,6 @@ static const TypeInfo scsi_disk_base_info = {
>>  };
>>  
>>  #define DEFINE_SCSI_DISK_PROPERTIES()                                   \
>> -    DEFINE_PROP_DRIVE_IOTHREAD("drive", SCSIDiskState, qdev.conf.blk),  \
>>      DEFINE_BLOCK_PROPERTIES_BASE(SCSIDiskState, qdev.conf),             \
>>      DEFINE_BLOCK_ERROR_PROPERTIES(SCSIDiskState, qdev.conf),            \
>>      DEFINE_PROP_STRING("ver", SCSIDiskState, version),                  \
>> @@ -2993,6 +2992,7 @@ static const TypeInfo scsi_disk_base_info = {
>>  
>>  static Property scsi_hd_properties[] = {
>>      DEFINE_SCSI_DISK_PROPERTIES(),
>> +    DEFINE_PROP_DRIVE_IOTHREAD("drive", SCSIDiskState, qdev.conf.blk),
>>      DEFINE_PROP_BIT("removable", SCSIDiskState, features,
>>                      SCSI_DISK_F_REMOVABLE, false),
>>      DEFINE_PROP_BIT("dpofua", SCSIDiskState, features,
>> @@ -3048,6 +3048,7 @@ static const TypeInfo scsi_hd_info = {
>>  
> 
> Does changing around the property order here break migration?

Yes, it will change the order. I'm not sure what it will affect.
So I think I should move 'drive' to the front to keep the original order.

I will change it in next version.

Thanks.

> 
>>  static Property scsi_cd_properties[] = {
>>      DEFINE_SCSI_DISK_PROPERTIES(),
>> +    DEFINE_PROP_DRIVE_IOTHREAD("drive", SCSIDiskState, qdev.conf.blk),
>>      DEFINE_PROP_UINT64("wwn", SCSIDiskState, qdev.wwn, 0),
>>      DEFINE_PROP_UINT64("port_wwn", SCSIDiskState, qdev.port_wwn, 0),
>>      DEFINE_PROP_UINT16("port_index", SCSIDiskState, port_index, 0),
>> @@ -3079,9 +3080,8 @@ static const TypeInfo scsi_cd_info = {
>>  
>>  #ifdef __linux__
>>  static Property scsi_block_properties[] = {
>> -    DEFINE_BLOCK_ERROR_PROPERTIES(SCSIDiskState, qdev.conf),         \
>> +    DEFINE_SCSI_DISK_PROPERTIES(),
>>      DEFINE_PROP_DRIVE("drive", SCSIDiskState, qdev.conf.blk),
>> -    DEFINE_PROP_BOOL("share-rw", SCSIDiskState, qdev.conf.share_rw, false),
>>      DEFINE_PROP_UINT16("rotation_rate", SCSIDiskState, rotation_rate, 0),
>>      DEFINE_PROP_UINT64("max_unmap_size", SCSIDiskState, max_unmap_size,
>>                         DEFAULT_MAX_UNMAP_SIZE),
>> @@ -3099,6 +3099,7 @@ static void scsi_block_class_initfn(ObjectClass 
>> *klass, void *data)
>>      SCSIDiskClass *sdc = SCSI_DISK_BASE_CLASS(klass);
>>  
>>      sc->realize      = scsi_block_realize;
>> +    sc->unrealize    = scsi_unrealize;
>>      sc->alloc_req    = scsi_block_new_request;
>>      sc->parse_cdb    = scsi_block_parse_cdb;
>>      sdc->dma_readv   = scsi_block_dma_readv;
>> @@ -3119,6 +3120,7 @@ static const TypeInfo scsi_block_info = {
>>  
>>  static Property scsi_disk_properties[] = {
>>      DEFINE_SCSI_DISK_PROPERTIES(),
>> +    DEFINE_PROP_DRIVE_IOTHREAD("drive", SCSIDiskState, qdev.conf.blk),
>>      DEFINE_PROP_BIT("removable", SCSIDiskState, features,
>>                      SCSI_DISK_F_REMOVABLE, false),
>>      DEFINE_PROP_BIT("dpofua", SCSIDiskState, features,
>>
>